This paper considers the most important factors that have played a role in the emergence and development of UFO religiosity and UFO alternative religious movements, from occult, spiritualist and theosophical teachings, to alternative ideas and debates on the origin of mankind. By analyzing the basic theological premises, the paper discusses the basic religious and culturological paradigms to be found in UFO movements. It also shows how a major part of their corpus can be recognized in existing "traditional" religious groups, and suggests that UFO religions represent just another variation on the numerous concepts that offer answers to key existential questions.